Process of separating the neutral oils in tars, tar oils, and pitches from acid constituents



Patented June 26, 1928.

UNITED STATES PATENT OFFICE.

HERBERT WITTEK, BEUTHEN, GERMANY.

PROCESS OF SEPARATING THE NEUTRAL OILS IN TARS, TAR OILS, AND PITCHES FROM ACID CONSTITUENTS.

No Drawing. Application fired April 14, 1927, Serial No. 183,893, and in Germany August 12, 1925.

The separation of the neutral constituents of tar, tar oil and pitch from the acid constituents, mainly phenolic bodies, has hitherto almost universally been effected by means of treatment with sodium hydroxide.

According to this invention the separation is effected by dissolving, with ethyl alcohol or other organic solvent, tar, taroil or pitch, for example crude coal tar, containing no paraflin or only little paraflin, and agitating the solution With paraflin oil or some oil mainly composed of paraflins. The paraflin oil extracts the neutral oils from the alcoholic solution. Layers are formed by the extraction, the layer containing the parafiin oil being almost free from phenol, and the alcoholic solution retaining nearly all the acid oils.

It has heretofore been proposed to make a substitute for petroleum jelly by extracting a jelly from pitch by means of a solvent such as alcohol, benzin'e, acetone, or other, the pitch being obtained from tar containing 50% or more of aliphatic hydrocarbons, and little, if any, aromatic hydrocarbon.

My process differs from this both in re gard to the raw material, which contains little or no paraffin, and in regard to the use of two solvents.

Instead of arafiin oil I may use any oil composed of ydrocarbons of the paraflin series, for example petroleum distillates. In place of ethyl alcohol I may use any other organic solvent or mixture of solvents capable of freely dissolving phenols and not miscible with the araffin oil or other solvent composed main y of paraflinsr; examples are tain two layers of condensate, one containing the alcohol and phenols, and the other the neutral oils.

The agitation with paraffin oil may be repeated as .required, and it is advisable thereafter, in order to complete the separa tion, to add to the alcoholic phenol layer a small percentage of water, and to shake the mixture Well. This separates the small amount of paraffin oil and other neutral oils retained by the alcoholic solution, leaving a solution of phenol free from neutral oils; the phenols can be separated bydistilling off the solvent.

The associated layers of neutral oils may be washed once or twice with their weight of Water, and then separated from the solvent paratlin by distillation, unless the mix ture is to be used as it is. The solvent containing paraflin oil can be re-used for sub sequent extractions.

Having now particularly described and as certained the nature of my said invention and in what manner the same is to be performed I declare that what I claim is 1. The process of separating oils from the acid constituents of tar, tar oil or pitch which is substantially free from paraflin, comprising confining the vapour of the tar, tar oil or pitch with vapours of an organic solvent for the acid constituents not miscible with paraffin oil, and vapours of an oil composed mainly of hydrocarbons of the paraflin series, agitating the vapours, condensing the vapours and separating the resulting layers.

2. The process of separating oils from the acid constituents of tar, tar oil or pitch which is substantially free from paraflin, comprising confining the vapour of the tar, tar oil or pitch with vapours of an organic solvent for the acid constituents not miscible with parafiin oil, and vapours of an oil composed mainly of hydrocarbons of the paraffin series, app ying pressure, agitatin the vapours, condensing the vapours and separating the resulting layers.

3. The process of separating oils from the acid constituents of tar, tar oil or pitch which is substantially free from parafiin,

comprising confining the vapour of the tar,'

tar oil or pitch with vapours of an organic solvent for the acid constituents not miscible with paraffin oil, and an oil composed mainly of hydrocarbons of the paraflin series, agitating the vapours, condensing the vapours adding water and again agitating, and then separating the resulting layers.

4. The process of separating oils from the acid constituents of tar, tar oil or pitch which is substantially free from parafiin,

comprising confining the vapours of the tar,

tar oil or pitch With vapours of an organic solvent for the acid constituents not miscible with paraflin oil, and vapours of an oil composed mainly of hydrocarbons of the paraffin series, agitating the vapours, and condensing them, separating the resulting layers, and distilling off the solvent.

- In testimony whereof I aflix my signature.

DR. HERBERT l/VITTEK. 

